OVERVIEW OF WATER RESOURCE ISSUES IN THE CARSON RIVER WATERSHED EDWIN JAMES, P.E. CWSD GENERAL MANAGER 2016

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1 OVERVIEW OF WATER RESOURCE ISSUES IN THE CARSON RIVER WATERSHED EDWIN JAMES, P.E. CWSD GENERAL MANAGER 2016

2 Carson River Watershed ~ 3,966 square miles Carson River miles Population: Current: 156,000 Predicted: > 300,000 by 2040 Limited Upstream Storage

3 CWSD History 1959 CWSD Established by the Court to Negotiate payback of debt on the Watasheamu Dam between the ranchers and Federal Government Douglas County and Lyon County join 1980s Federal Government abandoned Dam Project 1989 Nevada Legislator s changed CWSD s purpose 1989 Carson City Joins 1997 New Year s Flood Event 1998 Carson River Conference - Integrated Watershed Planning Implemented 1999 Churchill County Joins 2001 Alpine County California becomes a CWSD Member

4 Structure of CWSD 14 Board Members 6 counties / 2 states Funding Property Tax Grants (State, Fed., & others) Staffing 2 Full-Time 3 Part-Time

5 What We Do

6 Balancing Water Supplies Environmental Agricultural Domestic

7 Watershed s Current Water Supply Situation Fully appropriated 95 %+ for Agricultural Use Groundwater basins - over appropriated Actual GW pumping < Appropriated Limited Upstream storage Water quality problems Runoff Pattern Changes

8 Water Issues Perennial Yield vs. System Yield Wet Water vs. Paper Water Surface vs. Groundwater Interbasin Transfers Water Quality Use of Reclaimed Water Critical Management Area Climate Change

9 Perennial Yield versus System Yield What is Perennial Yield Limitation Regarding Perennial Yield System Yield Examples Carson City Eagle Valley Perennial Yield 4,900 AF System Yield 9,000 AF

10 Wet Water versus Paper Water Churchill Valley Groundwater Basin Pumpage Inventory Actual Category Committed Ground Water Resource (AF) Pumpage (AF) Irrigation 3, Commercial/ Stock/ Industial Quasi- Municipal 6, Domestic Wells N/A 1,405 Total 10,845 2,570 Perennial Yield = 1,600 AF System Yield =?

11 Surface Water versus Groundwater Groundwater Pumping impacts river flows but there s more to the story.

12 USGS Upper Carson River Study In 2009, USGS completed the study: Analysis of Streamflow Trends, Ground- Water and Surface-Water Interactions, and Water Quality in the Upper Carson River Basin, Nevada and California

13 Total Groundwater Pumping Upper Carson River Basin

14 USGS Findings GW pumping increased from < 8,000 AF/YR to 50,000 AF/YR Statistical analyses of mean annual streamflow changes were not measurable to Lahontan Reservoir Decrease in streamflow caused by increase pumping is offset by decrease in irrigation.

15 OTHER MAN MADE AND NATURAL CONSIDERATIONS Change in irrigation practices Laser-Leveling Fields Sprinkler Application Changes in runoff patterns Alpine Federal River Decree

16 Inter-Basin Transfers Inter-Basin Transfers have been happening for a long time in Nevada Marlette/Hobart System 1873 Intertie between Carson City/Dayton Intertie between Town of Minden & Carson City (Water Quality)

17 Ground Water Quality USGS Nitrate Study The Distribution and Modeling of Nitrate Transport in the Carson Valley Alluvial Aquifer, Douglas County, Nevada

18 Ruhenstroth Area - Douglas County

19 Use of Reclamation Water 27 % decrease of Reclaimed Water imported from Lake Tahoe since mid s. 14% decrease of local reclaimed water from the mid s to present. Majority of reclaimed water used for irrigating fields, parks, and golf courses.

20 CRITICAL MANAGEMENT AREAS Dealing with Critical Management Areas Sub-basins? Dealing with over allocated groundwater basins? Dealing with groundwater sub-basins where water levels are dropping?

21 GROUNDWATER ASSESSMENT Overall the groundwater basins in the Watershed are not being over drafted. There are areas of concern: Ruhenstroth area Fish Springs area Johnson Lane area Mark Twain area Stagecoach area South Silver Springs area Churchill County area

22 CLIMATE CHANGE

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25 Fraction of Annual Flow Runoff Changes Monthly Streamflow East Fork East Fork 0.00 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

26 The Stakeholder Affiliate Group Nevada Department of Water Resources Tahoe Regional Planning Agency The Nature Conservancy Truckee Meadows Water Authority Stillwater Wildlife Refuge Pyramid Lake Paiute Tribe Washoe Tribe Carson Valley Conservation District Carson River Subconservancy Truckee-Carson Irrigation District City of Fernley Fallon Shoshone Paiute Tribe

27 Questions? Photo by: Juan Guzman